The GMC Sierra 1500 III, specifically the Regular Cab Long Box configuration powered by the 4.8-liter Vortec V8 engine and a four-speed automatic transmission, was a mainstay of GMC’s full-size pickup truck lineup from 2010 to 2013. This variant represented a work-oriented, value-focused offering within the GMT900 platform, appealing to buyers prioritizing capability and affordability over luxury features. It served as a direct competitor to the Ford F-150, Chevrolet Silverado 1500, and Ram 1500 in the highly competitive North American full-size truck market.
Technical Specifications
| Brand | GMC |
| Model | Sierra 1500 |
| Generation | Sierra 1500 III (GMT900) Regular Cab Long Box |
| Type (Engine) | 4.8 Vortec V8 (302 Hp) Automatic FlexFuel |
| Start of production | 2010 |
| End of production | 2013 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 3 |
| Doors | 2 |
| Fuel consumption (urban) | 16.8 l/100 km (14 US mpg) |
| Fuel consumption (extra urban) | 12.4 l/100 km (19 US mpg) |
| Fuel Type | Petrol / Ethanol – E85 |
| Power | 302 Hp @ 5600 rpm |
| Torque | 414 Nm @ 4600 rpm (305.35 lb.-ft. @ 4600 rpm) |
| Maximum engine speed | 6000 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | L20 |
| Engine displacement | 4807 cm3 (293.34 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 96.01 mm (3.78 in.) |
| Piston Stroke | 83.06 mm (3.27 in.) |
| Compression ratio | 8.8:1 |
| Number of valves per cylinder | 2 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated engine |
| Valvetrain | OHV |
| Engine oil capacity | 5.7 l (6.02 US qt | 5.02 UK qt) |
| Coolant capacity | 12.7 l (13.42 US qt | 11.17 UK qt) |
| Max. weight | 2903 kg (6400.02 lbs.) |
| Trunk (boot) space – maximum | 2138 l (75.5 cu. ft.) |
| Fuel tank capacity | 128 l (33.81 US gal | 28.16 UK gal) |
| Length | 5702 mm (224.49 in.) |
| Width including mirrors | 2031 mm (79.96 in.) |
| Height | 1872 mm (73.7 in.) |
| Wheelbase | 3378 mm (132.99 in.) |
| Front track | 1732 mm (68.19 in.) |
| Rear (Back) track | 1702 mm (67.01 in.) |
| Ride height (ground clearance) | 228 mm (8.98 in.) |
| Minimum turning circle (turning diameter) | 15.4 m (50.52 ft.) |
| Approach angle | 15.4° |
| Departure angle | 24.1° |
| Ramp-over (brakeover) angle | 21.5° |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 4 gears, automatic transmission Hydra-Matic |
| Front suspension | Independent coil spring |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Disc, 330×30 mm |
| Rear brakes | Drum, 295×60 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Electric Steering |
| Tires size | 245/70 R17 |
| Wheel rims size | 7.5J x 17 |
Powertrain & Engine Architecture
The heart of this Sierra 1500 was the 4.8-liter (293 cubic inch) Vortec 4800 V8 engine, designated as the L20. This engine was a member of the Vortec family, known for its robust cast-iron block and cylinder heads. It featured a traditional overhead valve (OHV) valvetrain with two valves per cylinder. Fuel delivery was handled by a multi-port fuel injection system, providing adequate performance for typical truck duties. The L20 was also FlexFuel capable, meaning it could run on gasoline or a blend of up to 85% ethanol (E85). The engine’s 302 horsepower and 305 lb-ft of torque were considered sufficient for everyday hauling and towing, though not as potent as the available 5.3L or 6.2L V8 options. The engine was mated to a four-speed Hydra-Matic automatic transmission, a reliable but somewhat dated unit by the early 2010s. This transmission prioritized durability over fuel efficiency and offered smooth, if not particularly quick, shifts.
Driving Characteristics
The 4.8L V8 and four-speed automatic combination delivered a driving experience focused on practicality rather than sportiness. Acceleration was adequate for most situations, but the truck didn’t feel particularly quick. The automatic transmission’s gear ratios were tuned for towing and hauling, resulting in a lower first gear for improved off-the-line power but also contributing to a higher engine speed at highway cruising speeds. Compared to the more powerful 5.3L V8, the 4.8L felt noticeably less responsive, especially when fully loaded. However, the 4.8L’s lower power output also meant better fuel economy compared to its larger siblings. The ride quality was typical for a full-size pickup truck of the era – firm but generally comfortable, especially with a load in the bed.
Equipment & Trim Levels
The 4.8L Regular Cab Long Box Sierra 1500 typically served as the entry-level or mid-range trim. Standard features generally included air conditioning, a basic audio system, vinyl upholstery, and manual windows and locks. Higher trim levels, such as the SLE and SLT, added features like power windows and locks, upgraded audio systems, cloth or leather upholstery, and alloy wheels. Optional extras included a trailer hitch, tow package, and various convenience features. The interior design was functional and durable, prioritizing practicality over luxury.
Chassis & Braking
The Sierra 1500’s chassis was a traditional body-on-frame construction, providing a robust and durable platform. The front suspension utilized independent coil springs, while the rear suspension employed a solid axle with leaf springs. This setup was designed to handle heavy loads and provide a comfortable ride. Braking duties were handled by disc brakes in the front and drum brakes in the rear. Anti-lock brakes (ABS) were standard. The truck’s relatively high ground clearance and capable suspension made it suitable for light off-road use.
Market Reception & Comparison
The 4.8L Sierra 1500 was generally well-received by critics as a capable and affordable work truck. It offered a good balance of power, fuel economy, and durability. However, some reviewers noted that the four-speed automatic transmission felt outdated compared to the newer transmissions offered by competitors. Compared to the 5.3L V8, the 4.8L offered better fuel economy but significantly less power. The 4.8L was also a more attractive option for buyers who didn’t need the extra towing capacity of the larger engines. Its FlexFuel capability was a bonus for those seeking to utilize alternative fuels.
Legacy
The 4.8L Vortec V8, while not the most powerful engine offered in the Sierra 1500, proved to be a reliable and durable powertrain. These trucks are still relatively common on the used car market today, and well-maintained examples can provide years of dependable service. The four-speed automatic transmission, while not as sophisticated as modern transmissions, is known for its robustness. The 4.8L Sierra 1500 remains a popular choice for buyers seeking an affordable and capable full-size pickup truck for work or personal use. Parts availability is generally good, and maintenance costs are reasonable, making it a practical option for budget-conscious buyers.
